027-when-unless.lisp and related fix

          firstval

        (eval-list rest)))))

(defspecial unless (cond &rest body)

  "if COND yields nil, eval &rest BODY and return the result of the last"

(defspecial unless (cond &rest bodyforms)

  "if COND yields nil, eval &rest BODYFORMS and return the result of the last"

  (if (not (eval cond))

      (eval-list bodyforms)))

(defspecial when (cond &rest body)

  "if COND yields true, eval &rest BODY and return the result of the last"

(defspecial when (cond &rest bodyforms)

  "if COND yields true, eval &rest BODYFORMS and return the result of the last"

  (if (eval cond)

      (eval-list body)))

      (eval-list bodyforms)))

(defspecial cond (&rest clauses)

  (if (null clauses)

(defun false ()

  nil)

(defun true ()

  t)

(testcmp "when 0" '(when (false) (+ 13 14) (* 15 16) 332) nil)

(testcmp "when 1" '(when (true) (+ 13 14) (* 15 16) 332) 332)

(testcmp "when 2" '(let (a) (when (true) (setq a 115) 19) a) 115)

(testcmp "unless 0" '(unless (false) (+ 13 14) (* 15 16) 332) 332)

(testcmp "unless 1" '(unless (true) (+ 13 14) (* 15 16) 332) nil)

(testcmp "unless 2" '(let (a) (unless (false) (setq a 115) 19) a) 115)